Open and close ?les for writing, C/C++ Programming

If you have computed a number (stored as a ?oating-point value) and want to display this on a plot (i.e. as a character string) you have to convert it into a STRING. That is we want to convert between the two forms:



the ?rst is a ?oating point number (suitable for plotting or mathematical computation), and the latter is a 5-char string array (suitable for display using title or text commands, or which can be written to a ?le). For quick tasks MATLAB includes commands num2str, str2num, int2str and some others which can convert from numbers (?oating point or integer) to strings and vice versa but for best results one should learn how to use printf/scanf family of functions.

Note: One very important useage of fprintf is in program debugging. Adding in fprintf statements at crucial places in the program allows you to display the values of variables in a clean and elegant way without ?lling up the screen with numbers (which is what often happens when you simply remove the ; from the end of a line). We begin with fprintf, which outputs strings to the screen (sprintf works basically the same way but outputs data to a matlab variable, sscanf and fscanf read from strings or ?les). Here is a typical usage:>>fprintf('\nthis number %d and this one %.4f and these characters: %s\n\n',... 4,3.6,'qwerty')this number 4 and this one 3.6000 and these characters: qwerty  fprintf and sprintf take as ARGUMENTS a string containing a mix of characters and FORMAT SPECI-FIERS, followed by a number of variables (here their values are explicitly shown ). Format speci?ers begin with a '%', and end with a CONVERSION CHARACTER. There are lots of conversion characters but the ones you will use most are d for integers, e, f, and g for ?oating point numbers, and s for string data. Between the '%' and the conversion character there are various optional parameters, but most of the time you only need to use either a width (single number giving number of characters to use), and/or a precision after a decimal point (number of digits to right of '.'). If you don't specify these then MATLAB will try to do something sensible. The \n symbol represents a special 'non-printing' character - the CARRIAGE RETURN. It is non-printing because it isn't a letter or number, but it is used to say that the line has ended and the next characters will be on a new line.

Posted Date: 3/19/2013 3:23:47 AM | Location : United States

Related Discussions:- Open and close ?les for writing, Assignment Help, Ask Question on Open and close ?les for writing, Get Answer, Expert's Help, Open and close ?les for writing Discussions

Write discussion on Open and close ?les for writing
Your posts are moderated
Related Questions
how we can code in c++ for assignment problem (operation research) method to mkinimization and mamization

padovan string for natural numbers program in java // aakash , suraj , prem sasi kumar kamaraj college program 1 : package test.padovanstring; public class Padov

Differentiate between functions getch () and getche (). - Both functions accept a character input value from user. - When getch () is used, key that was pressed won't appear

This assignment document will be distributed from Blackboard assignment folder. Some parts of the assignments will require you to research answers from your text book (you must rea

Question Write a program using c++ for the above function , at a= 1000, b=10 -3 ,10 -2 ,10 -4

Write a function to determine whether a number is prime: it will return true if the input is prime and false otherwise. Use it to see whether -7 is prime.

Suppose we use Lists to represent a movie which has a title, cast and year. For example, the following list represents the movie, "Die Hardly", with the cast "Bruce Willing" and "T

At a shop of marbles, packs of marbles are prepared. Packets are named A, B, C, D, E …….. All packets are kept in a VERTICAL SHELF in random order. Any numbers of packets with thes

Program: Write a program that predicts users' age (0-128 years old) with at most 7 questions. The game starts with asking the user whether he/she is younger or older than G (an

How are postfix and prefix versions of operator++ () differentiated? A: The postfix version of operator++ () contain a dummy parameter of type int. The prefix version does not c